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Registers
672
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Enhanced Direct Memory Access (EDMA3) Controller
17.4.2.5.4 Chained Event Register (CER)
When the OPTIONS parameter for a PaRAM entry is programmed to returned a chained completion code
(ITCCHEN = 1 and/or TCCHEN = 1), then the value dictated by the TCC[5:0] (also programmed in OPT)
forces the corresponding event bit to be set in the chained event register (CER). The set chained event is
evaluated by the EDMA3CC logic for an associated transfer request submission to the transfer controllers.
This results in a chained-triggered transfer.
The chained event registers do not have any enables. The generation of a chained event is essentially
enabled by the PaRAM entry that has been configured for intermediate and/or final chaining on transfer
completion. The E
n
bit is set (regardless of the state of EER.E
n
) when a chained completion code is
returned from one of the transfer controllers or is generated by the EDMA3CC via the early completion
path. The bits in the chained event register are cleared when the corresponding events are prioritized and
serviced.
If the E
n
bit is already set and another chaining completion code is return for the same event, then the
corresponding event is latched in the event missed register (EMR.E
n
= 1). The setting of an event is a
higher priority relative to clear operations (via hardware). If set and clear conditions occur concurrently, the
set condition wins. If the event was previously set, then EMR would be set since an event is lost. If the
event was previously clear, then the event remains set and is prioritized for submission to the event
queues.
The CER is shown in
and described in
.
Figure 17-64. Chained Event Register (CER)
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
E31
E30
E29
E28
E27
E26
E25
E24
E23
E22
E21
E20
E19
E18
E17
E16
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
E15
E14
E13
E12
E11
E10
E9
E8
E7
E6
E5
E4
E3
E2
E1
E0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
LEGEND: R = Read only; -
n
= value after reset
Table 17-46. Chained Event Register (CER) Field Descriptions
Bit
Field
Value
Description
31-0
E
n
Chained event for event 0-31.
0
No effect.
1
Corresponding DMA event is prioritized versus other pending DMA/QDMA events for submission to the
EDMA3TC.